PVDF based flexible magnetoelectric composites for capacitive energy storage, hybrid mechanical energy harvesting and self-powered magnetic field detection

Abstract

Here we develop YFeO3-poly(vinylidene fluoride) (YFO-PVDF) based composite systems (with varied concentration of YFO in PVDF) and explore their multifunctional applicability including dielectric, piezoelectric, capacitive energy storage, mechanical energy harvesting, and magnetoelectric performances. The 5 wt% YFO loaded PVDF (5 YF) film has exhibited the highest polar phase percentage of ∼85%. On the other hand, the study of energy storage performance has shown the highest energy storage density for 3 wt% YFO loaded PVDF (3 YF) film. Owing to its highest polar phase and space charge polarization, the 5 YF film has shown the highest mechanical energy harvesting performance with open circuit voltages of ∼10 and 74 V and power densities of ∼2 and 47 μW/cm2 from the corresponding piezoelectric and piezo-tribo hybrid devices, respectively. The fabricated composite films have also shown good magnetoelectric (ME) properties with an ME coupling coefficient (α33) of ∼5.2 mV cm−1 Oe−1 (at 1 kHz frequency and 0.8 kOe applied DC field) for the poled 5 YF film. The application of an external magnetic field has shown the ability to tune the mechanical energy harvesting performances of both the piezoelectric and piezo-tribo hybrid devices which suggests their future application in self-powered magnetic field sensing.